chore: add btc to allowed bridge chain ids

[infiniteflower]

Explanation

This PR adds Bitcoin to the list of supported Bridge chains.

References

Related to https://consensyssoftware.atlassian.net/browse/SWAPS-2836

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes